A study of the elastic scattering of protons by B^(10)

[摘要] Protons elastically scattered by B^(10) have been studied in the proton energy range from 0.15 to 3.0 Mev. Angular distributions have been measured at 42 energies in this interval and excitation functions have been measured at center of mass scattering angles near 90°, 125° 16' and 160°. Subsidiary to these measurements, the atomic stopping cross section of boron for protons in the energy range from 0.10 to 3.0 Mev was determined with an absolute accuracy of 4%. The targets used in these experiments were produced through the thermal decomposition of diborane (B_2H_6).Theoretical analysis of the angular distributions indicates that for proton energies below 0.90 Mev the scattering can be described by pure s-wave potential scattering processes. There is no indication of anomalous scattering due to the previously reported states in C^(11) at excitation energies of 8.98, 9.13 and 9.28 Mev. Between proton bombarding energies of 0.90 and 1.6 Mev the scattering can be explained qualitatively with a broad J^ π = 5/ 2^+ level near 1.15 Mev, a J^ π = 7/ 2^+ level near 1.5 Mev, and a negative parity state formed by p-wave protons near 1.36 Mev. Although a definitive analysis was not obtained in this energy region, the two previously reported states in C^(11) at excitations of 9.74 and 10.09 Mev were not sufficient to explain the scattering.Above a bombarding energy of 1. 6 Mev the scattering angular distributions are compatible with a J^ π = 7/ 2^- state near 2.06 Mev with Γ_p/ Γ = 1, and Γ = 400 kev, and a J^ π = 7/ 2^+ state at some slightly higher energy. The analysis was not extended above 2.5 Mev.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics